Rotary hook sewing machine



March 9, 1954 3nveutor CZaFe/we 3?. BaakZd/U I Gttornegs Patented Mar. 9, 1954 ROTARY HOOK SEWING MACHINE Clarence R. Backlin, Floral Park, N. Y., assignor to Willcox. &. Gibbs Sewing Machine Company, New York, N. Y., a corporation of New York,

Application August 8, 1950, Serial No. 178,333

14: Claims.

This invention relates to sewing machines of the rotary hook type, and more particularly tothe stitching mechanism of such a machine, in'-- cluding the rotary hook, which is located below the bed and throat plate of the machine.

This stitching mechanism usually comprises the rotary hook, the hook shaft and driving means therefor, the bobbin case carried within the hook, and the bobbin case hanger and support therefor, which is employed to retain the bobbin case in operative position in the hook.

An object of the present invention is to provide an improved stitching mechanism of the above general character, which greatly facilitates the interchange and replacement of hooks, and the servicing of the hook, hook shaft and bearing assembly. This improved mechanism is characterized by removability of the hook and shaft. as a complete unit, this being made possible withoutrequiring extensive dismantling of the machine, or complicateddisassembly operations.

In accomplishing this I provide in accordance with the invention a novel and advantageous mounting for the hook. shaft, enabling the shaft and hook to be easily and quickly removed as a unit. from the frame of the machine.

Preferably the hook shaft is provided with a bearing and a drive gear, which are also removable with the shaft and also constitute a complete. unit therewith. Thus the problem of servicing the. hook and shaft assembly, and substituting different hooks in a machine is considerably simplified.

Another object of the invention is to provide an improved stitching mechanism of the above type, which provides for quick and easy removal and: replacement of the bobbin case.

A still further object of the invention is to provide an improved stitching mechanism as set forth immediately above, which is so arrangedasto prevent damage to the needle by the parts which are actuated to remove or replace a bobbincase.

accomplishing the above objects I provide a novel, improved pivotal mounting means for the: bobbin case hanger, having an interlock controlled by the kinetic machine mechanism geared to the needle. The interlock prevents the hanger mounting means from being; actuated if the needle is passing through and below the throat plate of the machine. Thus accidental damage or breakage of the needle as a consequence of swinging the bobbin case away from the rotary hook is averted.

The pivotal mounting for the hanger has its 2 axis disposed laterally of the rotary hookf and. above the lower-most portion of the hook, thereby reducing to a minimum the travelrequired' of the bobbin case to clear the hook when it is being swung away from the latter, and obviating the necessity for guides or auxiliary positioning means heretofore required. Moreover, the spacerequired by the hanger and mounting means therefor in swinging to their open positions greatly less as a consequence of such positioning of the pivotal axis.

A feature of the invention is the provision of Figure l is a view partly in elevationand partly invertical section, of the improved stitching mechanism of this invention.

Fig. 2 is a top view of the parts shownin Fig. 1

Fig. 3 is a fragmentary view-in vertical section of themanuallyreleasable lock in released position, and

Fig. 4 is an elevational View of the left end of the assemblage shown in Fig. 2.

Referring to Fig. 1, the sewing machine shown comprises a iced l0 having. a throat plate ll disposed adjacent the needle l2. Under the bed III a stitching. mechanism is. provided", comprising. a hook I3 carried. on a. hook shaft M.

In accordance with the present invention means:-

are provided for rotatably mounting the hook 131 and shaft ht on the underside of the; bed l0: ta enable said. hook and shaft. to be easilyamt quickly completely removed; as a unit. from: the

bed. This mounting means comprises a pair ofdepending supports 15 having aligned openings It, and further comprises a cylindrical bearing sleeve l1 carried by said supports and extending through the openings" [6 thereof. The bearing 7 sleeve" IT is retained in the supports by a releasable fastening means such. as set screws L8 as shown in Fig; 1, and may be readily removed from the supports when the screws [8 are loosened, by shifting it to the left as viewed in this figure.

The hook shaft 14 rotates in a pair of bushings I9 rigidly fixed to the bearing sleeve ll. On the shaft 14 a gear wheel or sprocket 26 is mounted, driven by a belt 2| which passes over a driving sprocket 22.

The bearing sleeve I1 has an oil hole Ila communicating with an oil chamber Ma in the sleeve located between the bushings I9 whereby the shaft 14 is adequately lubricated at all times.

By the above organization different shapes and sizes of hooks may be easily and quickly installed in the machine. To do this it is only necessary to remove the belt 2| and loosen the set screws l8. The entire assemblage of hook shaft and bearing sleeve, together with the gear 20 may then be removed as a unit by shifting it to the left as viewed in Fig. 1. 20 has a diameter slightly smaller than the apertures N of the supports l5, as shown, to enable it to pass through said apertures for the above purpose. 7

This organization is not only of considerable advantage in enabling different sizes and shapes of hooks to be quickly installed in a given machine, but it also enables the bearings for the hook shaft to be easily lubricated and serviced. Also, it enables the assemblage to be removed and interchanged without disturbing the oiling means for the hook shaft 14, as set forth above.

According to this invention a novel hanger supporting means is provided for mounting the hanger to retain the bobbin case in operative position within the hook l3, and for enabling quick and easy removal and replacement of the bobbin case without danger of damage or breakage of the needle during and as a consequence of such operation. This improved and simplified mounting means is so constituted as to be advantageously part of the removable assemblage of hook, hook shaft, bearing and driving means therefor set forth above.

In accomplishing this, referring to Figs. 1 and 2, the bearing sleeve I! at its left end is provided with a two-part articulated bracket 23 comprising a laterally extending arm 24 and a second and integral arm 25 at right angles to the arm 24. The arm 25 carries a headed pivot pin 26 which passes through and bears in it, the pin being secured by means of set screws 2'! to a second bracket part 23 having an upstanding portion 29 on which a hanger 30 of the usual type is carried. The hanger 30 is adapted to engage a bobbin case 31 and to retain the latter in an operative position within the hook 13, as will be well understood.

By virtue of the pivot pin connection between the bracket parts 25 and 28 the latter may be swung from an operative position shown in full lines in Fig. 1 to an open or inoperative position shown by broken lines. In this latter position the bracket part 28 will expose and make accessible the bobbin case 3| as indicated in Fig. 1, enabling it to be easily and quickly removed.

For the purpose of locking the bracket part 28 in its operative position and to enable the part to be easily and quickly shifted to open position,

a novel combined lock-release and actuating,

mechanism is provided, comprising an upright latch arm 32 carried in a slot 33 in the bracket part, said arm being pivotally mounted by means of a pin 34.

The latch arm 32 has an extension 35 projecting into a slot 36 of a locking plunger 37 carried The gear or sprocket 4 by the part 28 and adapted to project from the lower portion thereof as shown in Fig. 1. The plunger 3! is hollow and carries a helical compression spring 38 engaging the pivot pin 26 whereby the plunger is normally urged downward to projecting position.

The lower or projecting end 39 of the plunger is frustoconical in shape and is adapted to be received in a tapered hole 49 of a locking plate 41 which is rigidly secured to the underside of the bracket arm 25 by screws 42. When the plunger 31 is in its lower or projecting position and is accommodated in the hole 40 of the locking plate, the bracket part 28 will be locked in the operative position shown in Fig. 1. To release the bracket part 28 and swing it to open position it is merely necessary to grasp the upper end 32a of the latch arm 32, which is bent over in.the form of a handle, and to shift the latch arm to the left as viewed in Fig. 1 to the position shown in Fig. 3. This will first retract the plunger 3'! to release the lock or detent, and will then swing the bracket art 28 counterclockwise, Fig. 1, to the broken line position shown. This open position is determined by a stop screw 43 carried by the bracket arm 25 in a location to be engaged by the bracket part 28.

Closing of the bracket part 28, that is, shifting of the part clockwise (Fig. 1) to its opera,- tive position, is accomplished by reverse pres sure on the latch arm 32 or on the upstanding portion 29 of the bracket part.

For the purpose of preventing inadvertent damage to or breakage of the needle E2 during 1 the operation of swinging open the bracket 23 to remove the bobbin case, a novel interlock is provided comprising an extension 44 on the bracket part 28, having a projecting lug 45 extending across the face of an eccentric disk 46' carried by the lower shaft 41' of the machine Which normally carries the feed bar lift connection 43 actuating the feed bar 49. It will be understood that the lower shaft 4'! comprises part of the kinetic mechanism of the machine, being geared to the needle :2 in the usual manner. ment similar to that of the needle movement in that when the needle is raised the eccentricstop will be raised, and when the needle is lowered the eccentric stop will be lowered. Such a lowered position of the eccentric stop 46 is shown in Fig. 3, and the raised position of the eccentric sto is shown by the dotted lines in Fig. 3.

For the raised position of the eccentric stop the stop lug 45 will have a free path of movement in a downward are as indicated. Also when the eccentric stop 46 is in its lowered position it will interfere with the movement of the stop lug 45 and consequently prevent the bracket part 28 from swinging to open position. Thus whenever the needle l2 is in its downward position passing through the throat plate H, it will be. found impossible to swing the bracket to open quick and easy replacement and interchange of The eccentric disk or stop 46 has a movehooks. to be made. Also, lubrication and servicing of the bearing for the hook shaft is greatly simplified, since the entire bearing and shaft may be removed. as a single unit complete in and of itself.

The. organization described above also enables the bobbin case to be readily removed and replaced with a. minimum of time and inconvenience, and prevents breakage or damage of the needle due to manipuiation. of the parts during such replacement. The components by which the above results are accomplished are extremely simple and relatively inexpensive to manufacture and assemble. They are moreover rugged in construction and reliable in operation.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

Iclaim:

1. In a sewing machine of the type having a rotary hook disposed below a throat plate, having a needle which passes downwardly through the throat plate, and having kinetic mechanism geared with said needle, the improvement which comprises: a hanger to retain a bobbin case within the rotary hook; means pivotally mounting the hanger on the frame of the machine, enabling the hanger to be swung downward and away from the hook to expose the bobbin case for removal; and means located adjacent and engageable with the mounting means and actuated by said kinetic mechanism in timed relation to the operation of the needle, blocking said mounting means to prevent swinging of the hanger downward whenever the needle is below a predetermined raised position, thereby to prevent damage to the needle from movement of the hanger.

2. In a sewing machine having a bed provided with dependent supports, stitching mechanism comprising a rotary hook a, horizontally disposed hook shaft carrying said rotary hook; a bearing on said shaft, in which the shaft turns; and means, including releasable fastening means, mounting said bearing on the dependent supports for removal therefrom together with the shaft and rotary hook as a complete unit, when the fastening means is released.

3. In a sewing machine having a bed Provided with dependent supports having aligned openings, stitching mechanism comprising a rotary hook; a horizontally disposed hook shaft carrying said rotary hook; a gear carried by said shaft for driving the latter; a bearing on said shaft, in which the shaft turns; and means, including releasable fastening means, mounting said bearing in said openings for removal therefrom together with the shaft, rotary hook and gear as a complete unit, when the fastening means is released.

4. In a sewing machine of the type having a frame and a rotary hook thereon, the improvement which comprises: a hanger to retain a bobbin case within the rotary hook; means carried by the frame pivotally mounting the hanger on the frame of the machine, enabling the hanger to be swung downward and away from the hook to expose the bobbin case for removal; a latch arm pivotally mounted on said hanger-mounting means; a locking plunger axially movable on said hanger-mounting means; means connecting the latch arm to the plunger for advancing and retracting said plunger in response to opposite swinging movement of the latch arm; and means carried by the frame of the machine and positioned to cooperate with the plunger when the latter is advanced, for locking the hanger-mounting means inposition wherein the hanger ro tains the bobbin case in the hook; said plunger when retracted. releasing said mounting means to enable the hanger to be swung downward.v

5. In a sewing machine of the type. having .a rotary hook, the improvement which comprises:

a hanger to retain a bobbin case within the rotary hook; and means pivotally mounting: the hanger on th frame of the machine, enabling the hanger to be swung downward: and; away from the hook about a horizontal pivotalv axis. to expose the bobbin case for removal, the pivotal axis of said. mounting means being disposed laterally of the hook and below the center and; above thelowermost portion of the hook to reduce the space required by said mounting means in swinging. downward. to expose the bobbin case.

6. In a sewing machine, a rotary hook; ahook shaft carrying said: hook; a bearing for the hook:

shaft, in which the shaft turns; a hanger for retaining a bobbin case in the hook; meanscon nected with said bearing, supporting the hanger in operative position wherein it retains thev hob.- bin case in the hook; and releasable fasteningmeans mounting said bearing on the frame of the machine for removal therefrom together with the hook, hook shaft, hanger and hanger mounting means as a complete unit.

7. Ina sewing machine, stitching mechanism. comprising a rotary hook; a hook shaft carrying: said rotary hook; a gear carried by said. shaft for driving the latter; a bearing on said shaft; in which the shaft turns; ahanger to. retain. a. bobbin case within th hook; means pivotally mounting the hanger on the bearing, enabling; thehanger to be swung downward and away from the hook to expose the bobbin case for removal:

and means, including releasable fastening means,

mounting said bearing on the machine frame for: removal therefrom together with the. shaft, rotary hook, gear hanger and hanger-mounting means. as a complete unit, when the fastening: means is released.

8. In a sewing machine, stitching mechanism comprising a rotary hook; a hook shaft carrying said rotary hook; a bearing on said shaft, in which the shaft turns; a hanger to retain a bobbin case within the hook; means pivotally mounting the hanger on the bearing, said means enabling the hanger to be swung downward and away from the hook to expose the bobbin case for removal; positive locking means on said hangermounting means holding said hanger-mounting means in position wherein the hanger retains the bobbin case in the hook; manually operable means connected to said locking means for releasing said locking means and thereafter moving the hanger-mounting means to expose the bobbin case; and means, including releasable fastening means, mounting said bearing on the machine frame for removal therefrom together with the shaft, rotary hook, hanger, hangermounting means, locking means, and lock releasing means as a complete unit, when the fastening means is released.

9. In a sewing machine, a bed having a pair of depending supports provided with aligned apertures; a bearing carried in the apertures of said supports for complete removal therefrom; releasable fastening means maintaining the bearing in position in the supports; a hook shaft rotatably carried in said bearing; a hook mounted on said shaft; and a gear carried by said shaft for driving the latter, said gear having a, diameter less than that of the apertures of the support whereby the hook, hook shaft, bearing and gear may be removed as a complete unit from the frame by sliding the bearing out of the supports, the gear passing through the apertures of the supports during such removal.

10. The invention as defined in claim 8, in which there is a hanger to retain a bobbin case within the hook, and means pivotally mounting the hanger on the bearing, enabling the hanger to be swung downward and away from the hook to expose the bobbin case for removal, said hanger and mounting means therefor constituting part of the complete unit which is removable from the supports on the machine frame.

11. In a sewing machine of the type having a frame and a rotary hook thereon, the improvement which comprises: a hanger to retain a bobbin case in the rotary hook; means carried by the frame pivotally mounting the hanger on the frame of the machine, enabling the hanger to be swung downward and away from the hook to expose the bobbin case for removal; positive locking means on said hanger-mounting means and cooperable with the frame to hold said hangermounting means in a position wherein the hanger retains the bobbin case in the hook; and a com- A bined release and actuating means including a manually operable lever carried by the hangermounting means and connected to the locking means, said release and actuating means unlocking the hanger-mounting means and swinging the hanger downward and away from the hook in response to application of a force in one direction on the manually operable lever.

12. In a sewing machine, stitching mechanism including a unitary assembly comprising a rotary hook; a horizontally disposed hook shaft carrying said rotary hook at one end; a bearing sleeve in which said shaft turns and a drive means on the other end of said shaft, said sleeve intermediate its ends having an oil chamber through which the shaft passes, for lubricating the same; and means including a supporting 8 means and releasable fastening means, holding said bearing sleeve on the machine frame for removal from the supporting means together with the shaft, drive means and rotary hook as a complete unit, when the fastening means is released.

13. In a sewing machine having a bed, stitching mechanism comprising a rotary hook; a hook shaft carrying said rotary hook; and supporting means projecting below the undersurface of the bed and provided with means for releasably supporting the hook shaft for rotation in a horizontal position below the bed of the machine, said supporting means being provided with releasable fastening means for releasing the shaft for removal from the supporting means with the hook as a complete unit, upon release of said fastening means.

14. In a sewing machine having a bed, stitching mechanism comprising a rotary hook; a hook shaft carrying said rotary hook; a gear carried by said shaft for driving the latter; and supporting means projecting below the undersurface of the bed and provided with means for releasably supporting the hook shaft for rotation in a horizontal position below the bed of the machine, said supporting means being provided with releasable fastening means for releasing the shaft for removal therefrom with the hook and gear as a Number Name Date 1,020,041 Kiewicz Mar. 12, 1912 1,786,944 Hemleb Dec. 30, 1930 2,178,543 Rubel et al Nov. 7, 1939 2,219,210 Rubel Oct. 23, 1940 2,242,955 Karle May 20, 1941 

